Sodium tungstate is a kind of white shiny crystalline or crystalline powder, whose chemical formula is Na2WO4. It is weathered in the air. Also, it is insoluble in ethanol, slightly soluble in ammonia, and soluble in water, which is slight alkalinity. It is also known for its anti-diabetic effects. Sodium tungstate is prepared from tungsten ores used to manufacture tungsten by reducing it. It is used as catalyst for epoxidation of alkenes and oxidation of alcohols into aldehydes or ketones…
Tungsten Oxide
Metatungstic acid is a highly soluble and colorless crystal with a density of 3.93g/cm3. It is a kind of polytungstic acid with the formula H6 [H2 (W3O10) 4] ? nH2O, in which n is 10 or 23. It decomposes at 50°C. Its solubility is 88.57g/100cm3 (in water, at the temperature of 25°C). Metatungstic acid can be made from the salt of metatungstic acid (metatungstate). Metoplutamate is an important industrial product developed in the late 1970s. It is mainly used as…
Ammonium tungstate is a kind of white rhombic crystal, which is soluble in water and insoluble in ethanol. Its chemical formula is (NH4)10W12O41~xH2O. And It loses four molecular of crystal water at the temperature of 100℃. At the temperature of 20°C, its solubility in water is less than 2%. Ammonium tungstate is one of tungsten compounds and is an important intermediate material for tungsten metallurgy industry. It is an important raw material for producing ammonium paratungstate, ammonium metatungstate and phosphorus…
Ammonium paratungstate, APT for short, is a kind of white crystalline of flake or needle shape. Its chemical formula is (NH4) 10 (H2W12O42) ? 4H2O. And the CAS No. is 11120-25- 5, 14311-52-5. APT is insoluble in alcohol and is slightly soluble in water. Its solubility in water is less than 2% under the temperature of 20 °C. Ammonium paratungstate is usually in forms of pentahydrate and decahydrate. Chemical formula of pentahydrate is 5(NH4)2O?12WO3?5H2O. And chemical formula for decahydrate is…
High-purity tungsten trioxide has the purity of at least 99.99%, with chemical purity from 99.99% to 99.9999%. The content will be required respectively as for some special elements, such as radioactive, alkali metal, heavy metals and gas elements, ect. It is insoluble in water, soluble in alkali. The structure of high purity WO3 varies with temperature. They are triclinic, monoclinic, orthorhombic and tetragonal at different temperatures. Health hazards: low toxicity. It is irritant to the eyes and skin. Workers who…
Ammonium metatungstate, AMT for short, a kind of white crystallized powder, is mainly applied for petroleum industry. And it can also be used in the manufacture of various petrochemical catalysts and other tungsten compounds. Its molecular formula is (NH4) 6H2W12O40 ? XH2O. AMT is usually used as one of the precursors of tungsten carbide (WC) catalyst, and the properties of AMT precursor affect the morphology and size distribution of WC microsphere, which have a finally effect on the catalyst activity.…
Violet tungsten oxide, VTO for short, is powder shaped and violet displayed. VTO is mainly applied for the production of tungsten powder and tungsten carbide powder. It is produced by rotary calcining ammonium paratungstate at closely controlled temperatures in a reducing atmosphere. What is the morphological structure of VTO? VTO’s phase composition is WO2.72 (or W18O49), a different form of tungsten oxide, with unique crystal structure differing from other tungsten oxide’s. Its morphology is significantly different from the other three…
Blue tungsten oxide (BTO), also known as tungsten blue oxide (TBO) or β-tungsten oxide, is a compound of tungsten and oxygen. The measured density of BTO is 7.15g/cm3, the density measured by X-ray is 7.16g/cm3, and the range of homogeneous phase is WO2.8975~2.9014 (1000°C). Its formula is WO3-x. BTO’s composition is very complex, which may also exist WO2, WO3 and ammonium salts. Its most common form is WO2.9. BTO is manufactured by calcination of APT under more or less reducing…
Yellow tungsten oxide, YTO for short, has a yellow to bright green color. Its formula is WO3. It is used for the production of tungsten metal powder. Products passing 60 mesh screen. It keeps stable in the atmospheric temperature. Its apparent density is 2.3~2.8g/cm3. The crystal size is about 1.5um, it is yellow (made from tungstic acid) and is used as a catalyst. The crystal size is about 15um, showing bright green (made by calcining ammonium paratungstate), for the production…
Pyrochlore-type tungsten trioxide, also known as pyrochlore-type H2W2O7, can be used for the preparation of tungsten oxide, for laminated composite, for sensors and other fields. Its application to be developed because there is still no way to mass production. Its formula is H2W2O7 or WO3 ? 0.5H2O. Production method: 1. Hydrothermal synthesis method. Acidification of sodium tungstate solution to a certain pH range (pH> 3.5, and within the alkaline range), then, hydrothermal reaction to a certain time. 2. Adopt the…